Phone-Charging Microwaves

Phone-Charging Microwaves Just Another Breakthrough in Energy Harvesting

Earlier this year, an 18-year-old high school student from San Jose, California, created a gadget that can fully charge a phone in less than 30 seconds. Around the same time, researchers at the Kaner Lab at UCLA demonstrated how graphene can be cheaply made to produce a “super capacitor” capable of charging electronic devices in less than a minute.

Now, scientists at the University of Tokyo have developed an even more unusual method for charging electronics, and it involves the excess energy released by microwave ovens. The team, led by engineer Yoshihiro Kawahara, built an antenna that harvests ambient radio frequency (RF) signals and channels them into a separate electronic device.

Similarly, researchers at the University of Washington have discovered an ingenious way of recycling ambient energy. “Ambient backscatter,” as it’s called, draws power from ambient TV and cellular transmissions, and modifies the signals with its own data. The best part is it doesn’t require an additional power source or battery.

Collectively, these kinds of devices are called “energy harvesting (EH) systems,” and some scientists believe they could revolutionize the consumer electronics market. According to Navigant Research, sales of EH devices are to grow from less than 10 million units in 2013 to 18.7 million units by 2020. More importantly, EH devices are seen as an alternative to batteries.

The above-mentioned graphene super capacitor, although not exactly a battery, is a start. Recent breakthroughs in lithium-air technology have shown great promise, while newer innovations like molten-air batteries expand the field even further.

"There will be a place in the market for all of these different innovations,” by Kenyon Kluge(a lead engineer for Zero Motorcycles)